package face.pay.util;

import lombok.extern.slf4j.Slf4j;
import org.apache.commons.codec.binary.Hex;
import org.apache.tomcat.util.codec.binary.Base64;

import javax.crypto.*;
import javax.crypto.spec.SecretKeySpec;
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import java.util.UUID;

@Slf4j
public class AESUtils {

    public static  final  String defaultKey = "1254H778901234T6";

    private static final String KEY_ALGORITHM = "AES";
    private static final String DEFAULT_CIPHER_ALGORITHM = "AES/ECB/PKCS5Padding";// 默认的加密算法

    public  static  String Encrypt(String sSrc) {
        try {
            return encrypt(sSrc,defaultKey);
        } catch (Exception e) {
            log.error("加密错误",e);
        }
        return null;

    }

    public  static  String Decrypt(String sSrc) {

        try {
            return decrypt(sSrc,defaultKey);
        } catch (Exception e) {
            log.error("解密错误",e);
        }
        return null;
    }

    /**
     * AES 加密操作
     *
     * @return 返回Base64转码后的加密数据
     */
    public static String encrypt(String content, String key) {
        try {
            Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);// 创建密码器

            byte[] byteContent = content.getBytes("utf-8");

            cipher.init(Cipher.ENCRYPT_MODE, getSecretKey(key));// 初始化为加密模式的密码器

            byte[] result = cipher.doFinal(byteContent);// 加密

            return Base64.encodeBase64String(result);// 通过Base64转码返回
        } catch (Exception ex) {
            log.error("encrypt error",ex);

        }

        return null;
    }

    /**
     * AES 解密操作
     */
    public static String decrypt(String content, String key) {

        try {
            // 实例化
            Cipher cipher = Cipher.getInstance(DEFAULT_CIPHER_ALGORITHM);

            // 使用密钥初始化，设置为解密模式
            cipher.init(Cipher.DECRYPT_MODE, getSecretKey(key));

            // 执行操作
            byte[] result = cipher.doFinal(Base64.decodeBase64(content));

            return new String(result, "utf-8");
        } catch (Exception ex) {
            log.error("decrypt error",ex);
        }

        return null;
    }

    /**
     * 生成加密秘钥
     */
    private static SecretKeySpec getSecretKey(final String key) {
        // 返回生成指定算法密钥生成器的 KeyGenerator 对象
        KeyGenerator kg = null;

        try {
            kg = KeyGenerator.getInstance(KEY_ALGORITHM);

            // AES 要求密钥长度为 128
            kg.init(128, new SecureRandom(key.getBytes()));

            // 生成一个密钥
            SecretKey secretKey = kg.generateKey();

            return new SecretKeySpec(secretKey.getEncoded(), KEY_ALGORITHM);// 转换为AES专用密钥
        } catch (NoSuchAlgorithmException ex) {

            log.error("getSecretKey error",ex);

        }

        return null;
    }

    public static void main(String[] args) throws Exception {


        String content = UUID.randomUUID().toString();ReadFromFile.read("d://json.txt","utf-8");

                //加密
        System.out.println("加密前：" + content);

        String encryptResultStr =  Encrypt(content);
        System.out.println("加密后：" + encryptResultStr);
        System.out.println("密文长度：" + encryptResultStr.length());
        //解密
        String decryptResult = Decrypt(encryptResultStr);
        System.out.println("解密后：" + decryptResult);
    }

}

